Sorption Efficiency of Potentially Toxic Elements onto Low-Cost Materials: Peat and Compost

Author(s)

Lima, Jacqueline Zanin ^[1] ; Lupion, Renan Marques ^[1] ; Raimondi, Isabela Monici ^[1] ; Pejon, Osni Jose ^[1] ; Silvestre Rodrigues, Valeria Guimaraes ^[1]

Affiliation

^[1] Univ Sao Paulo EESC USP, Sao Carlos Sch Engn, Dept Geotech Engn, 400 Trabalhador Sao Carlense Ave, BR-13566590 Sao Carlos - Brazil

• Document type: Journal article
• Source: SUSTAINABILITY; v. 13, n. 22 NOV 2021.
• Web of Science Citations: 0

Abstract

Anthropogenic activities can lead to elevated concentrations of potentially toxic elements (PTEs) in soil and water. Thus, the search for low-cost, ecofriendly and innovative sorbents is a global necessity. The present investigation addresses the performance of peat and compost derived from the organic fraction of municipal solid waste (OFMSW) as a sorbent of zinc (Zn), lead (Pb) and cadmium (Cd). The physicochemical features and effects of the initial concentration (equilibrium) and contact time (kinetic) were systematically analyzed by batch experiments. In addition, human bioaccessibility tests were conducted to compare the human health risk of these PTEs postsorption. The results showed that the sorption capacities followed the order: compost(Pb) > peat(Pb) > compost(Cd) > compost(Zn) > peat(Cd) > peat(Zn), indicating that compost had a better sorption potential. Kinetic data were well-fitted to the pseudo-first-order (PSO), pseudo-second-order (PFO), and Elovich equation models. The external diffusion model proposed by Mathews and Weber (M \& W) indicated the contribution of diffusion as a sorption mechanism, mainly in the sorption of Zn, Pb and Cd onto compost and Pb onto peat. The bioaccessible fractions in the first stage (stomach conditions) were greater than those in the second phase (intestinal simulation). Pb has higher sorption capacities (10.511 and 7.778 mg g(-1) for compost and peat, respectively) and lowers fraction bioaccessible (35 to 70%). These findings demonstrate that utilizing these low-cost sorbents seems promising for the remediation of PTE soils and contaminated waters. However, more experiments should be conducted, including desorption and multielement solutions, as well as field-tests to prove the long-term effects of application in large-scale and real conditions. (AU)

• FAPESP's process: 17/16961-0 - Use of organic compost and peat in the retention of Pb, Zn and Cd and evaluation of the possible availability, toxicity and bioaccessibility of these metals after retention
• Grantee: Jacqueline Zanin Lima
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 14/07180-7 - Study of the soil contamination degree in the area of the former mining plant Plumbum (Adrianópolis, PR) due to the disposal of mining waste
• Grantee: Valéria Guimarães Silvestre Rodrigues
• Support Opportunities: Regular Research Grants
• FAPESP's process: 15/02529-4 - Geological-geotechnical characterization of reactive organic materials to be used in the retention of potentially toxic metals
• Grantee: Jacqueline Zanin Lima
• Support Opportunities: Scholarships in Brazil - Master